We don't blame you if you've been preoccupied with Priyanka Chopra's fairytale wedding photos today, but she's not the only one going all-out with beautiful, princess-worthy gowns this week. Over in London, all eyes were on Kate Middleton at Buckingham Palace during one of the most formal events of the year: a reception for the diplomatic corps.

For the white-tie occasion (that calls for even fancier looks than black-tie), the Duchess of Cambridge wore Princess Diana's iconic Lover's Knot tiara with a frothy bespoke Jenny Packham gown worthy of Cinderella. Middleton has only worn a tiara a handful of times, so the fashion moment was certainly special. Scroll down to see how Lady Di herself wore the tiara in the '80s and to revisit every time Middleton has worn a tiara to royal events.